Track scales with continuous rails and weighing sleepers

ABSTRACT

Continuous, uninterrupted rails for trains and the like having weight measuring sections. Weighing ties replace normal ties under the rails in the weight measuring sections. The weighing ties are of the same height, width, and external contour as the normal ties. The weighing ties include weighing cells that can be laterally adjusted to accommodate various rail gauges. The weighing ties include a housing made of steel plate with a floor, sides, and a top with an opening therein. The weighing cells protrude through the openings in the housings to support the rails in the weight measuring section. Transverse force sensors are also provided in transverse holes in both ends of the weight measuring sections of the rails to determine the power shunt. The weighing cells and transverse force sensors are prefabricated and calibrated to improve accuracy and durability of the weighing cells and force sensors.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to track scales with uninterrupted,continuous rails which are supported in a weighing section of line onseveral weighing sleepers.

2. Description of the Related Art

The purpose of such track scales is to weigh railway wagons as theytravel over the weighing section of line. In the interests of adheringto a preset weighing precision it is important that the wagons do notvibrate as they travel over the weighing section of line, because thiswould effectively falsify the weighing result. Accordingly, a longstraight section of track is required into which the weighing section ofline is incorporated. In this particular region the track bed should beas uniformly elastic as possible so as not to excite any vibrations.

Furthermore, the line nay not exhibit any shocks in this region. Theinfluence of leading and trailing wheels Is considerable and must bedetected in principle by the weighing system. Changes in the rigidity ofthe track bed may not cause any increase in the calibration error.

In the case of known track scales of the type initially described (U.S.Pat. No. 4,170,268) the sleepers in the vicinity of the weighing sectionof line are designed as special weighing sleepers. They essentiallycomprise double-T bearers which are laminated with wire Strain gaugesand are supported at their ends on a relatively large rail bedcomprising steel-reinforced concrete.

The bending strain of the double-T bearers detected by the wire straingauges delivers a mass of the weight forces acting on the rails by wayof the wagon wheels.

Since the line of rail runs uninterrupted, it is necessary to recordthose portions of the weight transferred by the rails in thenon-measuring normal sleepers adjacent to the weighing section of line,which represent a power shunt for weighing.

In many cases such track scales are incorporated into a line of rail asa subsequent measure, whereby the continuous rails remain Intact. Toincorporate the weighing sleepers the track bed in the vicinity of theweighing section of line must be partly removed and then replaced afterthe weighing sleepers have been set in. This means a change in therigidity of the track bed in the vicinity of the weighing section ofline. The larger deformations in the rail in this section are the causeof undesired vibrations of the wagons which render measuring resultsinaccurate.

Even when the track scales are not added at a later date, but areincorporated during railway construction, the substantially greaterstructural height of the weighing sleepers of the known track scales, ascompared to the normal sleepers, indicates a changed rigidity in thetrack bed in the vicinity of the weighing section of line.

SUMMARY OF THE INVENTION

In the case of the known track scales direct application of the wirestrain gauges to the double-T bearers of the weighing sleepers leads toincreased susceptance to failure, because it is very difficult toprotect these wire strain gauges adequately against environmentalinfluences. Besides, the material of the double-T bearers or of therails is little suited as a deformation body for a sensor contributingto the weighing process. The necessity of having to apply the wirestrain gauges under unfavourable conditions on site also impedesattainable weighing accuracy.

The double-T bearers of the weighing sleepers serving as weighingelements are relatively large components whose handling posesdifficulties during manufacture. Their rigidity is relatively low, sincethey are stressed according to the bending beam principle. This too canlead to substantial deviation In the rigidity of the line of rail in thevicinity of the weighing section of line compared to the adjacentregions. Disengaging disturbances, such as moments of flexion andtransverse forces, are not possible on the double-T bearers, or onlyinadequately so. The dimensions of the double-T bearers make theircapacity to be tested more difficult.

The operating procedures required on site at time of assembly of thetrack scales, in particular the application of the wire strain gauges,result in highly expensive and lengthy assembly, requiring prolongedblocking of the section of rail concerned. Subsequent shifting of thetrack scales is possible only at considerable expense.

The object of the present invention is therefore to produce track scalesof the type described at the outset, such that they can be incorporatedinto a section of rail easily and inexpensively by having theircomponents prefabricated to the greatest possible extent and inparticular such that there is no change in rigidity influencing theweighing result in the vicinity of the weighing section of line.

This task is solved by the present invention in that, in terns of theirheight and width, the weighing sleepers correspond to the normalsleepers which have been replaced in the weighing section of line andrespectively exhibit two weighing cells supporting both rails, and inthat transverse force sensors arranged at the ends of the weighingsection of line are prefabricated measuring elements introduced into atransverse borehole of the rail stem.

The effect of the weighing sleepers in terms of height and widthadapting to the normal sleepers is that due to exchange of the sleepersthere is no change to the native ballast underneath the sleepers andaccordingly no change in the rigidity of the ballast underneath theweighing section of line, as compared to the adjacent ballast. Thisapplies in particular where the track scales are Incorporated at a laterdate into an existing section of rail But even when the track scales arealready provided when the section of rail is being laid the constantexternal dimensions of the normal sleepers and of the weighing sleepersmean that the structure and the dimensions of the track bed areidentical in the vicinity of the weighing section of line and in theadjacent areas, so that there is no change In rigidity in the vicinityof the weighing section of line.

All measuring elements used for the weighing procedure, namely theweighing cells in the weighing sleepers and the transverse force sensorsset into the transverse boreholes of the rail stems, can be manufacturedusing customary manufacturing methods ensuring high measuring accuracyand can be checked prior to installation. Independent of the conditionand manufacturing quality of all the weighing sleepers weighing cellsare used for weighing which are optimised for this application and inparticular are free from interfering moment of flexion influences andtransverse force influences.

All components of the track scales can be easily dismantled withoutdamage and reused at another site. This enables the track scales to berelocated at relatively low expense.

According to a preferred embodiment of the invention provision is madefor each weighing sleeper to exhibit a sleeper housing, on whose housingfloor the weighing cells are supported which project through openings onthe upper side of the sleepers and bear the rails. This creates anarrangement of the weighing cells which has considerable protection,whereby the external contours and dimensions of the weighing sleeperscan be adapted to the normal sleepers to the greatest extent possible.

In particular, it is an advantage for the sleeper housings to at leastdisplay an external contour corresponding to the normal sleepers whichare replaced in the weighing section of line on the housing floor andthe connecting side walls of the housing.

An embodiment of the invention will now be explained In greater detailhereinbelow as illustrated in the diagram, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a section of rail in a longitudinal section, in which aweighing section of line is realised, and

FIG. 2 shows an enlarged section along line 11—11.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The section of rail illustrated in FIG. 1, in which a weighing sectionof line 1 is realised, presents uninterrupted continuous rails 2.Whereas rails 2 in the areas adjoining the weighing section of line 1 ina conventional manner rest on normal sleepers 3 in a ballast track bed4. rails 2 in weighing section of line 1 are supported on two or moreweighing sleepers 5. Each weighing sleeper 5 presents a sleeper housing6 comprising steel plate, as in the illustrated embodiment, on whosehousing floor 7 two weighing cells 8 are supported. Weighing cells 8project through openings 9 in the upper side of the sleepers and bearrails 2.

Weighing cells 8 are arranged such that they are insensitive to momentsof flexion and transverse forces. In their structure weighing cells 8correspond to conventional calibratable weighing cells. They arecalibrated during factory manufacture.

In terms of their height and width weighing sleepers 5 are adapted toadjacent sleepers, or to normal sleepers 3 which are replaced inweighing section of line 1. On housing floor 7 and connecting side walls10 of the housing they display at least an external contourcorresponding to the external contour of the replaced or adjacent normalsleepers 3.

With subsequent installation of track scales in a section of rail nochange is made to native ballast 4, on upper edge 4 a of which rest bothnormal sleepers 3 and weighing sleepers 5 inserted in their place. Inthis way ballast 4 retains its rigidity unaltered.

The same external contours of sleepers 3 and of weighing sleepers 5 alsoenable easy exchange. Normal sleepers 3 are withdrawn laterally in theprovided section of weighing section of line 1 and replaced by insertionof weighing sleepers 5, at which point rails 2 are fastened in place byuse of conventional fastening materials to fasten weighing cells 8likewise inserted laterally. The lateral adjustment of weighing cells 8to the gauge of rails 2 or the distance between rails can be madeeasily, as can the adjustment of weighing cells 8, precisely beneathrail 2. This is important for optional exchange of a weighing cell 8, orfor adapting each prefabricated, same-length sleeper housing 6 todifferent gauges.

For determining the power shunt with uninterrupted, continuous rails 2transverse force sensors 11 are incorporated at both ends of weighingsection of line 1. Transverse force sensors 11. likewise prefabricatedand factory-calibrated together with weighing cells 8, are introduced ina positive locking manner into transverse boreholes 12 of rail stems 13of rail 2. All that is required to mount transverse force sensors 11 isto realise transverse boreholes 12 on rails 2. Manufacturing transverseforce sensors 11 in the factory enables them to be designed such thatthey satisfy all requirements for a measuring element used in the field,such as density, temperature independence and easy assembly.

By running together any number of weighing sleepers 5 bogies and entirewagons can be weighed. Weighing errors are reduced by the resultinglonger measuring section and errors caused by weight transfer from oneaxle to the other are completely eradicated.

What is claimed is:
 1. Track scales with uninterrupted continuous railscomprising: a plurality of normal sleepers; a plurality of weighingsleepers interposed between and replacing normal sleepers in positionscorresponding to standard positions for the normal sleepers wherein theweighing sleepers have similar height and width as the normal sleepersand wherein the weighing sleepers each comprise two prefabricatedweighing cells supporting the uninterrupted continuous rails; a weighingsection of rail overlying the plurality of weighing sleepers andsupported by-the two prefabricated weighing cells of each weighingsleeper wherein the weighing section of rail has a transverse boreholepositioned at each end of the weighing section of line in a stem of therails; and transverse force sensors comprising prefabricated measuringelements introduced into the transverse boreholes.
 2. The track scalesof claim 1, wherein each weighing sleeper comprises a sleeper housinghaving a housing floor wherein the weighing cells are supported on thehousing floor so as to project through openings in an upper side of thesleeper housing such that the weighing cells bear the rails and whereinthe weighing cells can be shifted and adjusted laterally along thehousing floor.
 3. The track scales of claim 2, wherein the sleeperhousings is continuous with a U-shaped hollow cross-section and whereinthe housing floor and connecting side walls of sleeper housing have anexternal contour corresponding at least to corresponding sections of thenormal sleepers.
 4. The track scales of claim 1, wherein the weighingcells and the transverse force sensors are precalibrated.
 5. A railroadtrack comprising: a ballast track bed defining a plurality of sleeperpositions extending the length of the track; a plurality of normalsleepers positioned in outboard sleeper positions; at least two weighingsleepers interposed between the normal sleepers so as to occupy innersleeper positions wherein the weighing sleepers comprise at least twoweighing cells; at least two rails each having a stem section havingtransverse holes wherein the rails overlie and are supported by thenormal sleepers and the weighing cells of the weighing sleepers whereinthe rails extend in a continuous, uninterrupted manner the length of thetrack and wherein a section of track overlying the weighing sleepersdefines a weighing section of track having a first end and an opposite,second end; and a plurality of transverse force sensors positionedwithin the transverse holes in the stems of the rails and furtherlocated adjacent the first and second ends of the weighing section oftrack wherein the weighing cells and transverse force sensors areprefabricated.
 6. The track of claim 5, wherein the weighing cells andthe transverse force sensors are precalibrated.
 7. The track of claim 5,wherein the weighing sleepers further comprise a sleeper housing havinga floor, sides, and top wherein the top defines an opening and whereinthe weighing cells are supported on the floor and extend through theopening and wherein the weighing cells can be laterally adjusted on thefloor.